Electric transportation system

Abstract

An electric transportation system is disclosed. In one aspect, the system includes a wheel, a rechargeable battery having positive and negative poles, and a motor mechanically connected to the wheel and configured to generate a regeneration charge current, the motor including a coil. The system also includes a motor driver connected to the motor and the battery. The motor driver is configured to discharge the battery during a supply period so as to drive the motor and charge the battery with the regeneration charge current, wherein the motor driver includes a plurality of transistors electrically connected to the negative pole during a non-driving period. The system further includes a controller connected to the motor driver and configured to control the motor driver so as to drive the motor during the supply period and control the motor driver so as to charge the battery during the non-driving period.

The invention claimed is: 
     
       1. An electric transportation system comprising:
 a wheel; 
 a rechargeable battery having positive and negative poles; 
 a motor mechanically connected to the wheel and configured to generate a regeneration charge current, wherein the motor comprises a coil; 
 a motor driver connected to the motor and the battery and configured to i) discharge the battery during a supply period so as to drive the motor and ii) receive the regeneration charge current from the motor and convey the received regeneration charge current to the battery during a non-driving period, wherein the motor driver includes a plurality of transistors electrically connected to the negative pole; and 
 a controller connected to the motor driver and configured to i) control the motor driver so as to drive the motor during the supply period and ii) control the motor driver so as to charge the battery during the non-driving period, 
 wherein the controller is further configured to i) turn on the transistors connected to the negative pole during the non-driving, period so as to store the regeneration charge current in the coil and ii) turn off the transistors connected to the negative pole so as to charge the battery with the regeneration charge current, 
 wherein the motor driver is configured to receive a discharge current from the battery prior to the motor receiving the discharge current during the supply period, and wherein the motor driver is positioned between the battery and the motor, 
 wherein the coil comprises three phase coils electrically connected to the transistors, 
 wherein the transistors comprise first to sixth transistors, and 
 wherein the controller is further configured to i) turn-on the second, fourth, and sixth transistors during the non-driving period, ii) store a regeneration charge current in the three phase coils, iii) turn-off the second, fourth, and sixth transistors, and iv) charge the battery with the regeneration charge current stored in the three phase coils. 
 
     
     
       2. The system according to  claim 1 , wherein the controller is further configured to periodically turn on and off the transistors during the non-driving period. 
     
     
       3. The system according to  claim 2 , further comprising a speed sensor connected to the motor and controller and configured to i) sense a speed of the motor and ii) supply speed data to the controller, wherein the controller is further configured to set the supply period and the non-driving period based at least in part on the speed data. 
     
     
       4. The system according to  claim 3 , wherein the controller is further configured to change a turn-on time of the transistors electrically connected to the negative pole during the non-driving period based at least in part on the speed data. 
     
     
       5. The system according to  claim 4 , wherein the controller is further configured to shorten the turn-on time as the speed data value becomes greater. 
     
     
       6. The system according to  claim 1 , wherein the motor driver further includes a plurality of regeneration diodes each respectively electrically connected in parallel to the transistors. 
     
     
       7. The system according to  claim 6 , wherein pairs of the transistors are electrically connected in series to each other and in parallel to the battery. 
     
     
       8. The system according to  claim 7 , wherein each transistor includes first and second electrodes,
 wherein the first electrode of an odd number th  transistor of the pairs of transistors is electrically connected to the positive pole, and 
 wherein the second electrode of an even number th  transistor of the pairs of transistors is connected to the negative pole. 
 
     
     
       9. The system according to  claim 8 , wherein the second electrode of the odd number th  transistor of the pairs of transistors is electrically connected to the first electrode of the even number th  transistor of the pairs of transistors. 
     
     
       10. The system according to  claim 8 ,
 wherein a first terminal of each of the three phase coils is electrically connected to one another, and 
 wherein a second terminal of each of the three phase coils is electrically connected to a node between each pair of transistors. 
 
     
     
       11. The system according to  claim 1 , wherein the regeneration charge current stored in the three coils is configured to be transmitted to the positive pole through a plurality of regeneration coils each respectively electrically connected in parallel to the first, third, and fifth transistors. 
     
     
       12. The system according to  claim 1 , wherein the battery is configured to provide a driving current, and wherein the motor driver is configured to receive the driving current and provide the received driving current to the motor. 
     
     
       13. An electric transportation system, comprising:
 a rechargeable battery having positive and negative poles; 
 a motor configured to generate a regeneration charge current, wherein the motor comprises a coil; 
 a motor driver including a plurality of transistors and connected to the motor and the battery, wherein the transistors are electrically connected to the negative pole, and wherein the motor driver is configured to i) discharge the battery during a supply period so as to drive the motor and ii) receive the regeneration charge current from the motor and convey the received regeneration charge current to the battery during a non-driving period; 
 a controller configured to turn on the transistors connected to the negative pole so as to store the regeneration charge current in the motor and to turn off the transistors connected to the negative pole so as to charge the battery with the regeneration charge current during the non-driving period; and 
 a speed sensor connected to the motor and controller, wherein the speed sensor is configured to i) sense a speed of the motor and ii) supply speed data to the controller, wherein the controller is further configured to set the supply period and the non-driving period based at least in part on the speed data, 
 wherein the motor driver is configured to receive a discharge current from the battery prior to the motor receiving the discharge current during the supply period, and wherein the motor driver is positioned between the battery and the motor, 
 wherein the coil comprises three phase coils electrically connected to the transistors, 
 wherein the transistors comprise first to sixth transistors, and wherein the controller is further configured to i) turn-on the second, fourth, and sixth transistors during the non-driving, period, ii) store a regeneration charge current in the three phase coils, iii) turn-off the second, fourth, and sixth transistors, and iv) charge the battery with the regeneration charge current stored in the three phase coils. 
 
     
     
       14. The system according to  claim 13 , wherein the controller is further configured to periodically turn on and off the transistors during the non-driving period. 
     
     
       15. The system according to  claim 13 , wherein the motor driver further includes a plurality of regeneration diodes each respectively electrically connected in parallel to the transistors. 
     
     
       16. The system according to  claim 15 , wherein pairs of the transistors are electrically connected in series to each other and in parallel to the battery, wherein a first terminal of each of the three phase coils is electrically connected to one another, and wherein a second terminal of each of the three phase coils is electrically connected to a node between each pair of transistors. 
     
     
       17. The system according to  claim 16 , wherein the regeneration charge current stored in the three coils is configured to be transmitted to the positive pole through a plurality of regeneration coils each respectively electrically connected in parallel to the first, third, and fifth transistors. 
     
     
       18. The system according to  claim 13 , wherein the controller is further configured to shorten the turn-on time as the speed data value increases.